Gear-rolling machine.



H- N. ANDERSON. GEAR ROLLING MACHINE. APPLICATION FILED NOV-11,1913- Patented Sept. 25, 1917.

2 SHEETS-SHEET I.

H. N. ANDERSON.

GEAR RUL LING MACHWE. APPLICATION FILED NOV-11.!9l3- Patented Sept, 25, 191?.

ZSHEETHHEET 2. )5? x58 1 7 Mg I55 F5 5. /i ;i mv

, smaller cost than by any other.

particularly true of bevel gears, the producrarns T FFTQ.

HAR OLD N. ANDERSON, OF CLEVELAND, OHIO, ASSIGNOR TO THE ANDERSON ROLLED GEAR COMPANY, 01E CLEVELAND, OHIO, A CORPORATION OF OHIO.

GEAR-ROLLING MACHINE.

of the gear the blank is designed to mesh with, or it may be a roll which, though not like the gear the finished blank will be mated -with, is capable of forming teeth of the desired form and size on the blank. The embodiments of my invention herein shown are only adapted to roll teeth on bevel gears, but it is not therefore ".0 be inferred or understood that the invention is limited to that use.

The principal advantages derived from rolling teeth on gears are: First; the metal in the teeth, and in the. part of the gear adjacent to the teeth, is thereby rendered very dense andfine grained. Second; the grain, or fiber, of the metal is made to follow the contour of the teeth to a considerable extent, giving them very great strength. Third; a high degree of accuracy, both as to size and form of teeth, is assured. Fourth; gears can be produced by this method at a much This is,

tion of which has in the past been very expensive. Fifth; gears may be made of'materials which cannot be made into gears by any other process. Sixth; gears made of materials which are hardened by sudden chilling; such, for example, as'high carbon, steel, may be hardened to a considerable ex tent while they are being rolled. The die roll may be kept at a chilling temperature,

by a jet of cold air or water for this purpose.

While the valuable qualities of rolled gears are primarily due to the fact that they are rolled, these qualities, or at least part of them, are only attainable by maintaining synchronous relations between the teeth 'on.

Specification of Letters Patent. Patented Sept. 25, ll 91 '7.

Application filed November 11, 1913.

Serial No. 800,251.

I the die roll and the developing teeth on the blank while the latter are being formed. This synchronism may be maintained b driving the blank at such velocity that the imaginary line which, when the gear is finished, will be known as its pitch-line will move, from the beginning to the end of the tooth-forming operation, at the same velocity as the pitch-line of the die roll. Each of the structures herein shown is provided with means for this purpose.

In the accompanying drawings:

Figure l is a sectional elevation of one embodiment of my invention.

Fig. 2 is a diagrammatic view to demon strate the relative movements of the die roll and blank in the machine illustrated in Fig. 1.

Fig. 3 is a sectional plan of another em bodiment of my invention.

Fig. 4 is a view similar to Fig. 3, except that the die is in contact with the blank.

Before proceeding to the detailed description of these machines the following brief eXplanation of bevel gears will make the subject more easily understood: The teeth of bevel gears are constructed on imaginary pitch cones 1n the same way that the teeth of spur gears are constructed onimaginary pitch cylinders. The pitch cones of a pair of bevel gears would, if mounted on shafts -of the cones, measured on the side on which the contact between the cones takes place. The pitch diameter is the diameter of the base of the cone, and since the pitch of-a bevel gear is measured on a circle of the same diameter, Fpitch circle will be understood to mean a circle of the same diameter as the base of the cone. The pitch cone radius is the distance from the apex of the cone to the perimeter of its base. Treating the pitch circle as the perimeter of a plane, this imaginary plane will hereinafter be called the itch plane of the gear.

gear in place. rotates the sleeve 137, which, being screwed Referring now to Fig. 1, 125 is a frame carrying bearings 126 and 127. A. sleeve 128 is arranged to rotate in bearing 126, and is provided with a rigidly attached gear 129 which meshes with a driving gear 130, the latter in turn being driven by a belt 131. The lower end of the sleeve terminates in a timing gear 132, which meshes with a timing gear 133 carried by a sleeve 13-1 journaled in bearing 127. Each of the sleeves has Within it a shaft,-135 and 136 respectively,-capable of longitudinal movement, but which, by means of splines, is

made to rotate in unison with the sleeves.

The outer end of each shaft is reduced in diameter and passes through a sleeve 137, a nut and washer at the end of each shaft preventing longitudinal movement of the shaft with reference to the sleeve. That is, each sleeve is confined between the washer and the shoulder formed by reducing the diameter of the shaft. The sleeves are threaded and screw into threaded hubs 138 carried by .the frame 125. Outside of the hubs each sleeve 137 is connected by a spline to a bevel gear,139 and 140 respectively, said gears being mounted to rotate on pertions of the hubs extending beyond the frame. A set screw entering a groove in the hub which carries it keeps each bevel Rotation of the gear 139 into the hub 138, causes longitudinal movement of the sleeve and of the shaft 136 within it. At the same time, through the medium of gear 110 and the upper threaded sleeve 137, shaft 135 will be moved longitudinally. Obviously, if the lead of the threads on the sleeves 137 i; the same the relative distance the shafts move will be inversely proportional to the velocity ratio of gears 139 and 1 10. One of the shafts carries a die roll 141, and the other a blank 142. The sleeves 128 and 134 being immovable longitudinally the depth of ennieslnnent of the teeth of gears 132 and 133 does not vary as the shafts 135 and 136 advance longitudinally. The pitch-1ine velocity of the gears 132 and 133 being maintained without variation, it follows that the lineal velocity of the pitch-line of the dieroll 1-11 must be the same as that of the blank, 2'. 6., of the imaginary line which will be its pitch-line when it becomes a finished gear, all of the time the teeth are being.

rolled. Synchronism is therefore maintained between the teeth on the die-roll and the teeth it is forming on the blank.

Fig. 2 shows, diagrammatically, the relative movement required of the die-r011 and blank to make the approach pe pendicular to their pitch-cone radii. Assuming that their radii are equal they must move respectively distances, A' and B in order that their vertexes may arrive at the point V at Then the approach of each vertex to point V will be at such relative velocity that there wi 1 be no radial displacement of either the" die-roll or blank, one with reference tothe other; The effect, therefore,'is ust the'same as though they were movingtoward each other along a line perpendicular to their pitch-cone radii.

The most common form of bevel gear is that already described, in which the teeth are formed on an imaginary cone, the pitch-- cone angle being less than degrees. Increasing the number of teeth, the pitch and radius remaining-the same, increases the pitch-cone angle, and when the angle be comes 90 degrees the gear is what is known as a crown gear. The pitch-cone angle be ing 90 degrees theeone has in "fact been replaced by a pitch-plane, this plane, of course, being perpendicular to the axis of the gear. In the machine shown in Figs.

3 and =1 the die-roll and one of the timing gears is a crown gear. in this machine the blank 150 is secured in a recess formed in the timing gear 153, said gear being mounted on a shaft 151 arranged to rotate in a bearing 152. Theother timing gear, 154

a crown gear, is mounted-on a tubular shaft 155, which'rotates in a bearing 156. The die-roll, also acrowngear, is carried by a shaft 157 which is made to rotate in. unison with shaft 155 by means of a spline 158,, while fre to move longitudinally therein. Longitudinal movement isv imparted to itv by the hand screw 159. Bearin s 152 and 156 are secured. to a base (not 5 iown) and shaft 152 is rotated by means also not shown.

Synchronisin is maintained between the die-' roll teeth and-the developing teeth .on the blank by the g ars 153 and 154, whose depth of enmeshnient is not disturbed by the movement of-the die-roll. Since the pitchradius of the die-roll is perpendicular to its line of movement it is only necessaryto mount the blank-with its pitch-cone radius perpendicular to the axis of'the die-roll to insure movement of approach between the die-roll and blank perpendicular to} the pitch-cone radii. It will be obvious to any skilled mechanic that the die-roll and blank may, by very simple modifications in the means forfconnecting them to their respective timing gears, be transposed. For example, in Fig. 1 the die-roll might be mounted on shaft 136 and the blank on shaft 135. Or in Figs.',3 and 1 the blank might be mounted on shaft 157 and the die-roll, an ordinary beyel gear, on shaft 151, in which the blank would be a.-

.crown gear when finished. Furthermore,-

two gears adapted to run together might be mounted in place of the blank and die-roll, respectively, and run together for the purpose of smoothing up or polishing their teeth. Gears which have warped slightly in hardening might by this means be restored. If necessary an abrasive may be applied to the teeth while the gears are being run together.

Although I have disclosed the preferred embodiment of my invention it is not to be inferred that its application is limited thereto. It is limited only by the scope of the appended claims. follows:

1. In a gear rolling machine, a longitudi' nally movable die-roll adapted to roll teeth on gears, a longitudinally movable blank holder, means for moving them longitudinally, and means for compelling their longitudinal movement to be at a predetermined relative velocity.

2. In a gear rolling machine, a longitudinally movable die-roll adapted to roll teeth on a gear, a longitudinally movable blank holder, means for moving them longitudinally, and means for compelling their longitudinal movement to be at different velocities but at a predetermined ratio.

In a gear rolling machine, a longitudinally movable die-roll'adapted to roll teeth on gears, a longitudinally movable blankholder, means for rotating them at uniform velocity ratio concurrently with their longitudinal movement, means for moving them longitudinally, and means for compelling said longitudinal movement to be at a predetermined relative velocity.

4. In a gear rolling machine, a pair of bevel gears rotatably mounted with their teeth enmeshed, a toothed die-roll arranged to rotate in unison with and on the same axis as one of said gears, a blank-holder arranged to rotate in unison with and on the same axis as the other gear, means for moving the die-roll and blank-holder simultaneously longitudinally with reference to said gears, said means compelling the longitudinal movement to be at a predetermined ve locity ratio.

In combination, a pair of bevel gears rotatably mounted with their teeth enmeshed, a shaft in each gear whose axis coincides with the axis of the gear, said shafts being adapted to slide longitudinally with reference to the gears butsplined so as to rotate in unison therewith, and means for moving the shafts simultaneously in the gears at a n'edetermined relative velocity.

(5. In combination, a frame, a pair of bevel gears rotatably mounted (herein with their teeth enmeshed, a shaft in each gear whose axis coincides with the axis of the gear, the shafts being splined and adapted to slide longitudinally in the gears while What I claim is as and a gear arranged to rotate each sleeve in the threaded holes, said gears being enmeshed to an invariable depth. 7

7. In a gear rolling machine, a longitudinally movable die-roll adapted to roll teeth on a bevel gear, a longitudinally movable blank-holder, means for moving them longitudinally; concurrently with their rotation, and means for preventing radial displacement of the die-roll and blank, eachrelative to the other, during said longitudinal movement.

8. In a gear rolling machine, a longitudinally movable die-roll adapted to roll teeth on a bevel gear, a longitudinally movable blank-holder, means for rotating them and concurrently movingboth longitudinally for the purpose of rolling teeth on a blank carried by the blank holder, means for com.- pelling said longitudinal movement to be at a predetermined relative velocity, and means for maintaining synchronous relations between the teeth on the die-roll and the developing teeth on the blank.

9. In a gear rolling machine, means for supporting a blank, a die-roll, means for moving the die-roll longitudinally for the purpose of pressing it against the blank,

, and means for imparting relative movement between the die-roll and blank whereby they are rolled against each other.

10. In a gearrolling machine, rotatable means for supporting a blank, a die-roll, means for moving the die-roll longitudinally for the purpose of pressing it against the blank, and means for rotating the dieroll contemporaneously with said longitudinal movement.

11. In a gear rolling machine, means for supporting a blank, a dieroll, means for moving it longitudinally to press it against the blank, means for rotating the die-roll and blank, and means for maintaining fixed velocity ratio between them.

12. In a gear rolling machine, means for supporting a blank, a die-roll, means for moving it longitudinally and pressing it against the blank, means for imparting relative movement between the die-roll and blank whereby the die-roll and blank are made to roll against each other, and means for maintaining synchronous relations between the teeth on the die-roll and those it is forming on the blank.

13. In. a gearrolling machine, means for supporting a blank, a die-roll, means for imparting relative movement between the die-roll and blank, said movement including longitudinal movement of the die-roll,

whereby the die-roll teeth are pressed into and made to form teeth on the blank, and means for preventing radial displacement of the die1'0ll and blank, each relative to the other.

let. In a bevel-gearrolling machine, means for supporting a blank, a die-roll, means for rotating the die-roll and blank, means for contemporaneously producing relative movement of approach whereby the die-roll teeth are pressed into the blank, and means for causing said movement of approach to be perpendicular to the pitch-cone radii.

15. In a bevel-gear rolling machine, means for supporting a blank, a (lieu-oil mounted with its pitch-cone radius parallel. to What will be the pitch-cone radius of the finished blank, means for rotating the die-roll and blank, means for contomporaneousl} producing relative movement between the the roll and blank WllQl'QlJY the teeth of the fmmcr are pressed into the latter, and means for causing said approach to be perpendicular to said pitcl'ncone radii.

16. In a machine for rolling bevel gears, a pair of gears rotatably mounted With their teeth enmeshed, a blank-holder mounted to rotate in unison with one of said gears, a longitudinally movable die-roll mounted to rotate in unison with the other gear, means for imparting relative movement, including longitudinal movement of the die-roll,

whereby the die-roll is made to roll teeth on the blank, and means for preventing raative movement of approach whereby the die-roll and blank may be brought into con tact and teeth formed on the blank, and means for causing said approach to be perpendicular to said pitch-cone radii.

18. In a gear rolling machine, rotatable means for supporting a blank, a conical dieroll, means for rotating the die-roll and blank, means, comprising longitudinal move ment of the die-roll, -for producing relative moven'ient of approach between the die-roll and blanlngfor the purpose of pressing the die-roll teeth into and forming teeth on the rotating blank, and means for maintaining synchronous relations between the die-roll teeth and the developing teeth on the blank. In testimony whereof I ailix my signature in the presence of two subscribing Witnesse HAROLD N. ANDERSON.

i/Vitnesses R. M. CALFEE, F. A. BANKER. 

